Method of fish culture

ABSTRACT

Efficiency and economy of fish culture techniques all enchanced by destroying all undesirable fish species inhabiting a water body by treatment with juglone, allowing the juglone to degrade to form nontoxic components and thereafter introducing a desired species of fish into the water body.

United States Patent 72] Inventor Leif L. Marking Onalaska, Wis. [2|] Appl. No. 9,438 [22] Filed Feb. 6, 1970 [45] Patented Aug. 31, 1971 [73] Assignee The United states of America as represented by the Secretary of the Interior [54] METHOD OF FISH CULTURE 7 Claims, No Drawings [52] U.S. CI 119/3, 43/45 [51] lnt.Cl A0lk 61/00 [50] FieldotSearch ll9/l,2,3, 4; 424/331 X, 343

[56] References Cited UNITED STATES PATENTS 3,389,685 6/1968 MacPhee l19/3 X OTHER REFERENCES Auyong et al. Toxicon Pharmacological Aspects of .luglone" 1963 Vol. 1, Pages 235-239,Copy in ll9-3 Technical Survey, Vol. 23, No. 32,,Aug 26, 1967, Page 561 Lines 4-7 Copy in 43-45 Westfall et al. Science Depressant Agent from Walnut Shells Vol. l34, No. 3490, Page l6l7,Scien. Lib. 01.534

Primary ExaminerAldrich F. Medbery Attorneys Ernest S. Cohen and Roland H. Shubert ABSTRACT: Efficiency and economy of fish culture techniques all enchanced by destroying all undesirable fish species inhabiting a water body by treatment with juglone, allowing the juglone to degrade to form nontoxic components and thereafter introducing a desired species of fish into the water body.

Intensive and efficient development of fish breeding and culture techniques, both for commercial and sport purposes, generally requires complete control over the varieties of fish habitating the water bodies. In order to achieve such control, it is usually necessary to destroy all fish inhabiting a water body and afterward reintroduce fish of the desired species. Generally, this is accomplished by chemical poisoning of all of the fish within a water body.

A number of fish poisons or piscicides have been developed and are in common use. Many of the chlorinated hydrocarbons used as agricultural insecticides also have piscicidal properties. For example, toxaphene (chlorinated camphene having the approximate formula C I-l CI is known to be lethal to fish at field concentrations in the range of 5 to 35 p.p.b. However, a minimum of about 7 months is required for this chemical to degrade or be diluted to nontoxic concentrations.

Other chemicals used as piscicides include rotenone and antimycin A. Rotenone has the disadvantage of also destroying organisms important as fish food. Antimycin A is a powerful fish toxicant, efi'ective for killing most scale fishes at concentrations of 10 p.p.b. or less. However it does not control ictulurids, such as catfish and bullheads, at reasonable concentrations. Additionally, antimycin A is often not sufficiently persistent in high pH waters to be completely effective.

SUMMARY OF THE INVENTION plished in a variety of conventional ways including sublimatron.

Juglone has been known as a compou ntfior over lfi fi years and an extensive literature concerning its uses and properties has developed. Many investigators have recognized and reported phytotoxic effects of this compound. Biological activity of the compound toward a wide variety of plants and animals has also been extensively noted. The compound is also known to have a depressant effect on fish and in some cases, investigators have reported juglone to kill fish at relatively low concentrations.

However, up to this time, the unique combination of properties displayed by juglone when used as a piscicide has not been recognized. J uglone kills a wide variety of fish, including the common American trash fish such as carp and bullheads, at relatively low concentrations. Toxic action of the com pound is relatively rapid and is not significantly afiected by water temperature, hardness or pH. Juglone is sufficiently persistent to produce a thorough and complete fish kill but degrades rapidly enough in the natural environment to allow restocking with desired species shortly after treatment.

The following examples illustrate the invention in more. detail.

EXAMPLE I The effect of varying concentrations of juglone on a number of different species of fish was determined. Bioassays were conducted according to the methods of Lennon and Walker (Investigations in Fish Control: 1. Laboratories and methods for screening fish-control chemicals, US Bureau of Sport Fisheries and Wildlife, Circular I85, 1964). Observations on mortality were made at 3 and 6 hours on the first day, and daily thereafter for the remainder of the 96-hour test period. Water used for these tests was a standard assay water having a pH of 7.2 to 7.6; total hardness as CaCO of 40-48 ppm. and a total alkalinity as CaCO, of 30-35 p.p.m.

Results of those bioassays are as follows:

TABLE 1.I()XICITY ()F JUGLONE T0 FISH IN STANDARD BIOASSAYS AT 12C.

L(,5O 11ml (MS-percent cmillllvnclinterval in p.p.h. ut- Man zspecies 3 hours 6 hours 24 hours 48 hours 90 hours funzii n Rainbw mm Sazm" as. 243% 00, @7 21? .1 1? 2 g 1. 12 Nmthem Pike Em s9. s-iz s i 50.12312 2e. 24.7%?1 22. eg Goldfish Oarmflm 712. 0-1, 32118 323. 04 3318 sao-iigli 79. 3-133; 71, s-giIg --------------------------------3211:2131: 3220-33218 H331 ass-133:3 was-182:3} White suck" Cawmm commersom 281. ($3313 137. sig ass-Z1 15 57. 8- /2? 53, 5-2913 i 37 Black bullhesd WW Mat --l:::::::::::.'::: 521. 5.2352 104. tiiiifi 69.5.3335 61.7.5312 Channel catfish Wmmms- 141252315 781-2219 316-2113 31, 1.131; 31 1X21; sunfish 7161mm cl/mlm 2631-223 0 112. viii: (i 51. 04 ,812 131$; 131$? i Bhwgm Lemma mamchm" mas-E g: 1311. s-igii 483-22; 11.1-3? 316.1513 i Hence, it is an object of this invention to provide a method of fish culture. I A specific object of this invention is to provide a method for .the removal of unwanted varieties of fish from water bodies so as to enhance its value for either sport or commercial fish production.

3 DETAILED DESCRIPTION OF THE INVENTION Juglone (S-hydroxy-l,d-napthoquinone) can be isolated from walnut husks of .luglans nigra, J. cinerea, J. regia or Juglandaceae or it can be synthesized by oxidation of 1,5- dihydroxynaphthalene. Extraction of juglone from walnut hfisks may beaccor nplished by leaching with ether or other s ol ents. Purification of tl 1 crude extract may be accom- As may be seen from the table, juglone was highly toxic to all nine species of fish, representing seven genera, which were used as test subjects. The LCSOs (that concentration at which 50 percent of experimental fish were killed) in the 9-hour bioassays ranged from 27 to 88 p.p.b. (parts per billion). Rainbow trout and northern pike were among the most sensitive species while goldfish, carp and black bullheads were most resistant. Mean slope functions were determined for each species. This function is derived from a plot of percent mortality versus juglone concentration; a slope function of I being a vertical line. A low value of the slope function indicates that small increases of concentration drastically increases mortality. Thus, for each species, juglone produced complete mortality or permitted complete survival over a narrow range of concentrations.

EXAMPLEZ These data indicate that juglone is inactivated with time h f both in buffered and nonbuffered bioassay solutions, but not Effect of quamy.and iempgmture e 3.2 0 so quickly that target species survive. it is apparent that juglone toward fish was mvesngate A num r o I erem degradation and breakdown of juglone occur in the natural assay waters rangmg from j Soft hard were.prepared environment to form nontoxic or less toxic components. Makeup of these assay waters is set out in the followtng table: Conventional techniques may be employed for the use of TABLE 2.COMPOSITION OF ASSAY WATERS Concentration as Salt added in mg. pcr l. p.p.m. CaCO;

Classification pll Total Total 0i wntt'r NnllCO: (21180 M11801 K01 range hardness alkalinity bittlll p 12 7.5 7. Pl 0. ii (Li-(Hi -13 10-13 hltllllliurtl 4H 30.1! iii). II 2.1] 7. 2-7. ii iii-4K 30-35 M0diul|l.. Hi2 120.0 120.!) iii) 7.6-8.1] liiil ll'iil llil-l2U Hard 384 240. (l .Z-ill. 0 iii. 0 8. (Hi. 4 280-320 225-245 1 Standard reconstituted water used in routine liloassay.

Bioassays were performed using these waters in the same juglone in fish culture. Since juglone is nonnally a solid, it is manner as was set out in the preceding example. Effect of most conveniently applied as a dilute solution in any solvent water temperature in the range of 7 to 22 C. on the toxicity which is at least partially miscible with water. As with any of uglone was also determined. Results of these tests are set other piscicide, application to a water body must be perout m the followmg table: fo rmed in such a manner that the juglone is distributed rela- TABLE 3.-TOXICITY 0F JUGLONE TO F1811 AT DIFFERENT TEMPERATURES AND WATER HARDNESS L050 and 95-pcrccnt confidence interval in p.p.b. at- Mean Temp. Water slope Species C. hardness 3 hours 6 hours 24 hours 48 hours 96 hours function 85. 0 00. 0 40. 7-52. 0 40. 7-52 3116-23. 3 2 2.0 24.0 00.0 56. Bluegill 12 248. 0 171. 0 8. 52. 0. 12 Hard i As may be seen from the table, rainbow trout respond Isimilarly to juglone at the three test temperatures: 7, l2 and tively uniformly throughout thewater mass. in the case of a pond or lake, juglone is most conveniently applied by .17 C. This indicates the compound to be effective throughout dispensing a solution of the chemical from a boat. Flowing the general range of temperatures normally encount red in streams may be treated by metering the chemical into the ;trout habitats. Water hardness had no appreciable effect on water at a rate proportional to the stream flow.

gthe toxicity of juglone toward trout except that there was an Concentration of juglone in the water beingtreated must be indication that toxicity dropped slightly in the very hard water. sufficiently high to kill all target species within a reasonably Biuegills were found to react similarly to trout in waters of short time; preferably within about 24 hours. if the target spegdiffering temperature and hardness. Toxicity of juglone cies include such relatively resistant fish as carp and bulltoward bluegills does not appear to vary significantly over the heads, then juglone concentrations used must .be somewhat =range of water temperatures and hardness tested. These data 55 higher then for other species. Generally treatment levels will .indicate that juglone is effective in hard, alkaline waters which be in a juglone concentration range of about 50 toabout 500 gtend to inactivate other common piscic desp.p.b. A preferred treatment level is in the range of about I00 i to about 300 p.p.b.

i EXAMPLE 3 After treatment of the water body with juglone, it is l in order to be considered as a practical piscicide, not only preferred that dead and dying fish be removed and suitably imust a chemical be highly toxic to fish but it must degrade in disposed of to avoid water degradation. it is necessary to delay ithe environment at a relatively rapid rate to nontoxic forms. restocking the water body with fish of a desired species i'orfia .However. the chemical must also be persistent enough to time auil'tcient to allow the juglone to degrade to less toxic and thoroughly and completely eradicate target species. These nontoxic components. This time period between treatment c i 1 racteristics ofjuglone are illustrated in the following table. and restockingwilLdepend primarily upon two factors; the.

TABLE 4.THE EXTENT OF DEGRADATION OF JUGLONE WITHIN ONE WEEK IN STANDARD AND BUFFERED WATER AT 12 0. AS INDICATED BY THE TOXICITY TO RAINBOW TROUT LCBO and lb-percent confidence interval in p.p.b. at

Degradation time y Test water 3 hours 6 hours 24 hours 48 hours 96 hours 94 66 39 38 36 o Standard 5 0-111 58-75 36-2152 30 21 33-31 1 standa d. pH-M 4 Buflered 02339010 404 4. N M011. Md 25 i.- 1 11. 101 939002492300 the delay between treatment and restocking will vary from about to 60 days. As an' added safety measure, it is sometimes appropriate to test the residual water toxicity prior to restocking. This may be easily accomplished by taking sample of the water and observing the behavior of a few fish placed in the water sample over a period of several days. If the fish show no signs of depressed physical activity, then residual juglone levels are sufficiently low to permit restocking in safety.

What I claim is:

l. A method of fish culture which comprises treating a body of water with juglone at a concentration in the range of about 50 to about 500 p.p.b. so as to produce a toxic environment and thereby destroy all undesirable species of fish inhabiting the water. allowing the juglone to degrade into components nontoxic to fish and thereafter introducing a desired species of fish into the treated water body.

2. The method of claim 1 wherein the juglone is in the form of a relatively dilute solution.

3. The method -of claim 2 wherein introduction of the desired fish species is delayed for at least about 10 days after treatment of the water body with juglone.

4. The method of claim 3 wherein the water body is treated with juglone at a concentration in the range of about 100 to 

2. The method of claim 1 wherein the juglone is in the form of a relatively dilute solution.
 3. The method of claim 2 wherein introduction of the desired fish species is delayed for at least about 10 days after treatment of the water body with juglone.
 4. The method of claim 3 wherein the water body is treated with juglone at a concentration in the range of about 100 to about 300 p.p.b.
 5. The method of claim 4 wherein the juglone solution is metered into a flowing streaming at a rate proportional to the water flow in the stream.
 6. The method of claim 4 wherein introduction of the desired fish species is performed within about 10 to about 60 days after treatment of the water body with juglone.
 7. The method of claim 4 wherein the water body comprises hard, alkaline water. 